openmp: Introduce gimple_omp_ordered_standalone_p

On Sat, Sep 03, 2022 at 10:07:27AM +0200, Jakub Jelinek via Gcc-patches wrote:
> Incrementally, I'd like to change the way we differentiate between
> stand-alone and block-associated ordered constructs, because the current
> way of looking for presence of doacross clause doesn't work well if those
> clauses are removed because they had been invalid (wrong syntax or
> unknown variables in it etc.)

The following, so far only lightly tested, patch implements that.

2022-09-06  Jakub Jelinek  <jakub@redhat.com>

gcc/
	* gimple.h (enum gf_mask): Add GF_OMP_ORDERED_STANDALONE enumerator.
	(gimple_omp_subcode):  Use GIMPLE_OMP_ORDERED instead of
	GIMPLE_OMP_TEAMS as upper bound.
	(gimple_omp_ordered_standalone_p, gimple_omp_ordered_standalone): New
	inline functions.
	* gimplify.cc (find_standalone_omp_ordered): Look for OMP_ORDERED with
	NULL OMP_ORDERED_BODY rather than with OMP_DOACROSS clause.
	(gimplify_expr): Call gimple_omp_ordered_standalone for OMP_ORDERED
	with NULL OMP_ORDERED_BODY.
	* omp-low.cc (check_omp_nesting_restrictions): Use
	gimple_omp_ordered_standalone_p test instead of
	omp_find_clause (..., OMP_CLAUSE_DOACROSS).
	(lower_omp_ordered): Likewise.
	* omp-expand.cc (expand_omp, build_omp_regions_1,
	omp_make_gimple_edges): Likewise.
gcc/cp/
	* pt.cc (tsubst_expr) <case OMP_ORDERED>: If OMP_BODY was NULL, keep
	it NULL after instantiation too.
gcc/testsuite/
	* c-c++-common/gomp/sink-3.c: Don't expect a superfluous error during
	error recovery.
	* c-c++-common/gomp/doacross-6.c (foo): Add further tests.

1 files changed, 23 insertions, 1 deletions

diff --git a/gcc/gimple.h b/gcc/gimple.h
index 1d15ff9..77ac149 100644
--- a/gcc/gimple.h
+++ b/gcc/gimple.h
@@ -194,6 +194,7 @@ enum gf_mask {
     GF_OMP_RETURN_NOWAIT	= 1 << 0,
 
     GF_OMP_SECTION_LAST		= 1 << 0,
+    GF_OMP_ORDERED_STANDALONE   = 1 << 0,
     GF_OMP_ATOMIC_MEMORY_ORDER  = (1 << 6) - 1,
     GF_OMP_ATOMIC_NEED_VALUE	= 1 << 6,
     GF_OMP_ATOMIC_WEAK		= 1 << 7,
@@ -2312,7 +2313,7 @@ static inline unsigned
 gimple_omp_subcode (const gimple *s)
 {
   gcc_gimple_checking_assert (gimple_code (s) >= GIMPLE_OMP_ATOMIC_LOAD
-			      && gimple_code (s) <= GIMPLE_OMP_TEAMS);
+			      && gimple_code (s) <= GIMPLE_OMP_ORDERED);
   return s->subcode;
 }
 
@@ -2402,6 +2403,27 @@ gimple_omp_section_set_last (gimple *g)
 }
 
 
+/* Return true if OMP ordered construct is stand-alone
+   (G has the GF_OMP_ORDERED_STANDALONE flag set).  */
+
+static inline bool
+gimple_omp_ordered_standalone_p (const gimple *g)
+{
+  GIMPLE_CHECK (g, GIMPLE_OMP_ORDERED);
+  return (gimple_omp_subcode (g) & GF_OMP_ORDERED_STANDALONE) != 0;
+}
+
+
+/* Set the GF_OMP_ORDERED_STANDALONE flag on G.  */
+
+static inline void
+gimple_omp_ordered_standalone (gimple *g)
+{
+  GIMPLE_CHECK (g, GIMPLE_OMP_ORDERED);
+  g->subcode |= GF_OMP_ORDERED_STANDALONE;
+}
+
+
 /* Return true if OMP parallel statement G has the
    GF_OMP_PARALLEL_COMBINED flag set.  */